The present invention relates to a self-standing container such as a so-called xe2x80x9cstand pouchxe2x80x9d which can stand by itself when its bottom is expanded by being filled with a content and, more particularly, to a self-standing container which prevents the immigration of air or the like by blocking the inflow of the air with a check valve and which prevents any discharge of the content even at an accidental impact or the like.
In the prior art, for the storage of beverages that have their taste deteriorated by oxidation, such as wine, sake, whiskey, fruit beverages, and vegetable juices, glass bottles have been used which are sealed with large-sized cork stoppers or screw caps. However, these glass bottles are heavy and brittle so that they are seriously troublesome to handle. It is, therefore, the current practice to use PET bottles made of plastic in place of the glass bottles.
These hard containers, as represented by the PET bottles, are hardly reduced in their own capacities as their contents are reduced. Therefore, the hard containers are highly stationary as containers and can be used as pressure-resisting containers according to their shape. Thus, the hard containers offer a feature in that they can also be used as pressure-resisting containers for carbonated beverages or the like.
Like the glass bottles or the like, however, the hard containers such as the PET bottles will establish cavities as their contents are reduced, and the cavities will be occupied by air so that the contents are oxidized with the air. Therefore, the hard containers are not suited for storing the beverages effected by contact with the air, such as wine, sake, whiskey, fruit beverages, and vegetable juices.
On the other hand, the hard containers always have constant capacities so that they themselves always occupy a constant amount of space, no matter whether or not they have contents. It is easily understood how wasteful this is, if a case in which a container that is filled with a beverage is stored in a refrigerator is imagined. Where a 1 liter container containing 200 cc of water is stored in a refrigerator, a volume of 800 cc of the container occupies the refrigerator as wasted space.
With an increase in consciousness of environmental protection in recent years and, on the other hand, with a view towards getting rid of disposable containers, more inexpensive bag-shaped containers have been employed for rebottling, instead of the PET bottles, especially for home detergents. Most of the bag-shaped containers for these purposes are the self-standing containers called xe2x80x9cstand pouchesxe2x80x9d because they are easily displayed at shops.
Thus, we had an idea that the stand pouch containers are used in placed of the PET bottles, and have made various investigations. We have found out to mount a pouring port in the stand pouch container and to attach a check valve to the pouring port. Then, this check valve is opened to allow the contents to migrate when subjected to a pressure in the direction to pour the contents and is closed when subjected to a pressure in the filling direction.
At this time, especially the upper portion of the inside of the self-standing container formed of a soft sheet is automatically subjected to a vacuum by the downward flow phenomenon due to the gravitational force of the contents. By this vacuum, moreover, the check valve is closed when the pressure is applied in the filling direction of the self-standing container (to suck the contents), so that the container can prevent the intake of air. In other words, this self-standing container can be said to be a so-called xe2x80x9cvacuum container having a suction preventing function in the vacuumxe2x80x9d for preventing the inflow of air at all times.
Here, it has been found that this self-standing container retains its self-standing property only while it is filled up with the contents. It has also been found that the container has its capacity reduced and loses its self-standing property as the content is reduced, and that a bag-shaped container 200 having lost its rigidity, as shown in FIG. 9, folds midway such that its head collapses, thereby raising a problem in that the bag-shaped container falls down and is hard to handle.
The present invention has an object to provide both the so-called xe2x80x9cself-standing type bag-shaped vacuum containerxe2x80x9d capable of preventing the immigration of air at all times and a stand pouch type container which retains the advantage of flexibility and high capacity efficiency, as belonging to that of the prior art, and which has a self-standing property when the content is reduced as is absent in that of the prior art.
In the hard container of the prior art, such as a glass bottle or a PET bottle, on the other hand, the pouring rate could always be controlled to be constant by gripping the container firmly with the hands of a user and by controlling the tilting angle of the bottle.
Here, the hard container of the prior art is not or slightly deformed when gripped with the hands, and no internal pressure is established in the container so that the content is not vigorously discharged, but is poured out.
Recently, however, a bag-shaped container having a cylindrical pouring port has been used especially as a beverage container. The bag-shaped container is made flexible and foldable, and has its entire capacity reduced as the content is reduced. Therefore, this container is able to reduce the amount of waste by folding and disposing of it.
However, the soft container, such as the bag-shaped container described above, is flexible so that an internal pressure is easily established, when the container body is squeezed, to discharge the content vigorously. This characteristic is a defect intrinsic to a soft container body of the bag-shaped container or the like. Therefore, when the content is transferred from the bag-shaped container to another container, the content is poured not by squeezing the container body of the bag-shaped container, but by gripping and tilting the outer edge of the container body, by applying the pouring port to the inlet port of the container without spilling the transferred content, and by pushing the container body to pour the content. However, this handling is so troublesome that the content will be vigorously discharged, thereby causing a spill unless special care is taken. On the other hand, a fall has to be feared at all times so long as the soft container stands by itself.
Therefore, the present invention has been contemplated to solve the above-specified problems and has an object to provide a bag-shaped container which is freed from any vigorous discharge of the content even if its body is carelessly squeezed and which can take the place of the hard container of the prior art, such as the glass bottle or the PET bottle.
According to the invention, more specifically, there is provided a self-standing type bag-shaped vacuum container comprising a self-standing container including a wall formed of a soft sheet and a bottom made expandable when filled with a content, so that it can stand by itself, a pouring port disposed in the end portion of the self-standing container formed of the soft sheet, and a check valve mounted in the pouring port. The check valve is opened to allow the migration of the content when subjected to a pressure in the pouring direction, but is closed when subjected to a pressure in a filling direction, so that the inside of the container is evacuated by the vacuum which is established by the weight of the content in the self-standing container formed of the soft sheet.
According to the invention, there is provided a self-standing bag-shaped container comprising a wall formed of a soft sheet, and a pouring port so that it can stand by itself when its bottom is expanded by filling it with a content. A check valve is disposed in a cylindrical member forming the pouring port for preventing the backflow of air as the content is discharged. The container is evacuated at its upper portion, when the container is placed upright after the content is discharged, by the downward migration of the remaining content due to gravitational force.
Moreover, the check valve has a structure in which a domed head has a cut that is opened when a pressure is applied in the pouring direction, to allow the migration of the content, but is closed, when a pressure is applied in the filling direction, to prevent the inflow of air or the like. Alternatively, outward folds are formed to extend downward from the pouring port to the self-standing container formed of the soft sheet.
In addition, the self-standing bag-shaped container further comprises a joint structure for jointing a sheet member forming the bag-shaped container body and a cylindrical member forming the pouring port, in that the cylindrical member is inserted into a heat-shrinkable first cylindrical sheet so that these two members are jointed by heat-shrinking the first cylindrical sheet. The container also comprises a second cylindrical sheet including two layers of a resin layer fusible to the sheet member on its outer side jointed in the lower portion of the first cylindrical sheet, and an infusible resin layer on the inner side which is fused to the sheet member.
Moreover, the container further comprises a flow velocity control mechanism including a flow velocity control unit having a vent hole for communication with the container body between the container body and the pouring port, to eliminate the flow velocities of the content in the inflow direction when the content flows into the flow velocity control unit from the inside of the container body through the vent hole.
Still moreover, the container further comprises a flow velocity control mechanism including a plurality of vent holes opposed to each other in a flow velocity control unit so that the content flowing into the flow velocity control unit may impinge upon itself to offset the flow velocity in the inflow direction.
Furthermore, the container further comprises a flow velocity control mechanism including a wall disposed in a flow velocity control unit and intersecting the inflow direction from a vent hole at a right angle so that the content flow may be impinged, when the content comes from the inside of the container body into the flow velocity control unit, upon the wall, to eliminate the flow velocity in the inflow direction.
The self-standing container such as the stand pouch of the invention has the construction thus far described so that it can be optimized for storing not only wine, sake or whiskey, which are effected by contact with air because they will be oxidized with the air, but also fruit beverages, vegetable juices or other beverages. The invention can provide a vacuum type container which will not lose its self-standing property even if the content is reduced and can stand stably by itself.
It is quite natural for the container like the stand pouch to be used not merely as a disposable container, but as a self-standing container in place of the bottle type container which has a pouring port and can be reused. Where the container is used as the self-standing container, no matter how much it contains. The container can be kept in the upright position with its bottom being expanded. When the container is not used, on the other hand, it can be easily stored in a flat bag shape by folding the bottom.
It is also possible to provide such a soft container represented by the bag-shaped container provided with the flow velocity control mechanism for preventing the content from being vigorously discharged by internal pressure generated when the container body is squeezed.